Tag: databases

Questions Related to databases

Using INSERT command only ONE record can be inserted during each execution.
technology databases

  1. True

  2. False

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Correct Option: B

What is true about MERGE command? Choose all that apply.

technology databases

  1. It is a DML command

  2. It is a DDL command

  3. Provides the ability to conditionally update or insert data into a database table

  4. Provides the ability to MERGE VIEWS and INDICES of a TABLE

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Correct Option: A,C

Select TYPES of JOINS. Choose all that apply.

technology databases

  1. EQUI-JOIN

  2. NONEQUI-JOIN

  3. SELF-JOIN

  4. OUTER-JOIN

  5. MERGE-JOIN

  6. TRANSACTION-JOIN

Show answer
Correct Option: A,B,C,D

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) EQUI-JOIN - This option is correct. An EQUI-JOIN is used to combine rows from two or more tables based on a related column between them.

Option B) NONEQUI-JOIN - This option is correct. A NONEQUI-JOIN is used to combine rows from two or more tables based on a condition that is not an equality.

Option C) SELF-JOIN - This option is correct. A SELF-JOIN is used to join a table to itself, treating it as two separate tables.

Option D) OUTER-JOIN - This option is correct. An OUTER-JOIN is used to combine rows from two or more tables, including unmatched rows from one or both tables.

Option E) MERGE-JOIN - This option is incorrect. A MERGE-JOIN is not a type of join. It is a technique used in query optimization to merge sorted data sets.

Option F) TRANSACTION-JOIN - This option is incorrect. A TRANSACTION-JOIN is not a type of join. It does not exist in the context of SQL joins.

The correct answer is A, B, C, and D. These options are correct because they represent different types of joins commonly used in SQL queries.

Choose the MANDATORY clauses of SELECT SQL statement
technology databases

  1. SELECT

  2. WHERE

  3. GROUP BY

  4. FROM

  5. ORDER BY

  6. HAVING

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Correct Option: A,D

ALIAS can be used for TABLE as well as COLUMN to simplify interpretation of SQL query

technology databases

  1. True

  2. False

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Correct Option: A

Identify the correct output select INITCAP('ORACLE BASICS') from dual;

technology databases

  1. ORACLE BASICS

  2. Oracle Basics

  3. oracle basics

  4. oracleBasics

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Correct Option: B

Identify the correct output --- select CONCAT('ORACLE' || 'BASICS') from dual;
technology databases

  1. ORACLE BASICS

  2. ORACLEBASICS

  3. oraclebasics

  4. oracleBasics

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Correct Option: B

Identify the correct output --- select SUBSTR('ORACLE BASICS',-6,5) from dual;

technology databases

  1. BASIC

  2. BASICS

  3. E BAS

  4. ORACL

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Correct Option: A

Identify the correct output --- select TRUNC(TO_DATE('01-SEP-1995', 'DD-MON-YYYY'),'YEAR') from dual;
technology databases

  1. 01-SEP-1995

  2. 01-JAN-1995

  3. 01-JAN-1996

  4. 1995

  5. 1996

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Correct Option: B

Identify the correct output --- select ADD_MONTHS(TO_DATE('01-SEP-1995', 'DD-MON-YYYY'), 6) from dual;
technology databases

  1. 01-MAR-1996

  2. 01-FEB-1996

  3. 07-SEP-1995

  4. 06-SEP-1995

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Correct Option: A